Stop PRs from gaming the system

I know of second generation PRs who renounced their PRs, skip NS and studied and worked a number of years abroad and after that came back to Singapore to work and live again, as PRs. Surely it would be a deterrent if the government resolutely refuses to allow such people from ever living in Singapore again whether as Employer pass holders, or PRs or even new citizens. I sense that the government makes exception for certain people depending on their qualifications. If we make exception, people will always try particularly if they are averse to the idea of NS. If we make it an absolute no-no, I am sure they may not even try. And if they do decide they won’t they will have to accept the consequence that comes with it e.g. not ever going to leave with their parents in Singapore again. That would be a great deterrent. Comparing the situation, the Singaporeans who avoided NS or ...